The present invention relates in general to data acquisition instruments for detecting the motion activity of an individual using and simultaneously correlating the motion activity parameters, such as blood pressure, pulse rate and alike with the detected motion activity.
In the medical field it is often useful to monitor patients while they carry on with their daily activities. This permits the correlation of parameters having a clinical interest, such as blood pressure, heart rate, etc., to the actual physical activity being performed during the daily activities. This monitoring and data acquisition is also extremely useful for medical research purposes because it allows more complete data to be obtained as compared to the data obtained in an ambulatory environment under unnatural and/or constricting conditions.
Unfortunately, it is not easy to obtain such measurements if the patient is exerting himself physically since the recorded measurements may provide unreliable data because of the difficulty of correlating the various measurements to the current physical activity. Typically, the patient is recommended to write in a diary the time the daily activities are performed, especially when the carried instrument actually takes a reading. However, this hinders which types of chores the patient may perform, and if these types of chores are performed, this practice may lead to voids and/or imprecisions in the recordings.
The ideal situation would be to combine to the instrument measuring the physiological parameters having a clinical interest with a device capable of automatically detecting the physical activity being performed by the patient. This information would be classified and stored along with the readings periodically taken and recorded. In this way, when the apparatus is given to the patient and properly installed to carry out correct measurements, the patient may indeed lead a normal life without worrying about the measurements being taken.
An approach of this type would be extremely advantageous because of a greatly enhanced reliability of the data. There would be perfect synchronization between the detection and classification of the physical activity being performed and the measurement having a clinical interest. In this way, the parameterization of data as a function of the current state of the physical exertion would be extremely more accurate as compared to the patient who tries to quantify himself in the same physical activities.
This approach would provide all the advantages that only an automatic data acquisition instrumentation can guarantee. It is evident that there is a need and/or utility for an automatic system for detecting and storing parameters representative of the current state of physical exertion of the patient, particularly during prolonged periods of monitoring in a totally instrumental manner without causing discomfort to the monitored patient.
It is an object of the present invention to provide an automatic system that can be carried or worn by a person for acquiring and recording data on the movement of one or several parts of the person""s body. The movement is detected by a corresponding number of sensors placed on respective parts of the person""s body so that the motion may be monitored. This fulfils in a optimal manner the above-noted needs and requisites.
Fundamentally, the automatic system according to the invention comprises one or more motion sensors applied to respective parts of the body of the subject being monitored. An analog-digital converter associated with each sensor converts the analog signal generated by the sensor into digital data. A logic block calculates predefined parameters from successive time sequences of the digital data for each sensor.
The automatic system further includes first fuzzy logic means for processing the calculated parameters and for generating corresponding fuzzy logic labels of classification of the motion sensed by each of the sensors during the same time interval of observation. A storage memory stores the parameters and/or fuzzy labels.
Second fuzzy logic processing means are provided for classifying the overall motion activity of the monitored subject based upon the sets of fuzzy labels relative to the different motion sensors, and for outputting an index representing that the physical activity has been performed in the time interval of observation.
The use of fuzzy logic processing is extremely effective because the task is to assess quantities that are difficult to quantify, i.e., fuzzy. This type of processing is greatly enhanced by using fuzzy logic that is ideally structured for managing situations that are not sharply defined.